JPH0427798A - Fixing device for impeller - Google Patents

Abstract

PURPOSE:To enable the fixing device in the title to be fixed and removed from a impeller shaft easily as well as excellency in workability and producibility at a low cost by applying turn stop to the impeller through a process of tightening an annular wedge by means of a tightening nut. CONSTITUTION:An axial hole 3 in which an impeller shaft 1a fits loosely is protrusively set in the boss part 2b of an impeller 2 to set a slant pressure receiving surface 5 circumferentially around the axial port 3 eccentrically in front of the axial hole 3. And, the slant pressing surface 7 of an annular wedge 6 is inserted from the tip of the impeller shaft 1a along a slant pressure receiving surface 5. The slant pressure receiving surface 5 is pressed by the slant pressing surface 7 by tightening a tightening nut 8 fitted spirally at the tip of the impeller shaft 1a in its axial direction, and one side of the inner peripheral surface of the axial hole 3 is in eccentric pressure contact with one side of the outer peripheral surface of the impeller shaft 1a. Thus, fitting and removal to and from the impeller shaft 1a can be easily performed as well as excellency in workability and producibility at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fixing device for an impeller in a submersible pump or the like.

[Prior art and its problems] Conventionally, in order to fix the impeller to the impeller shaft, generally,
A key groove carved on the outer periphery of the impeller shaft that slides into the shaft hole,
A key groove carved on the inner periphery of the impeller boss portion is opposed to the opposing portion, and a detent key is fitted into the opposing portion.

However, carving these keyways is extremely difficult to process, and requires precise grinding of the sliding surface between the impeller shaft and shaft hole, which is an obstacle to producing pumps at low cost. .

As a measure to fix the impeller without using a locking key, an annular wedge 6' is inserted between the impeller shaft 1'a and the shaft hole 3', as shown in Figs. 12 to 16. There are also some that did. According to this device, the impeller shaft 1'
By tightening the tightening nut 8' screwed onto the tip of a in the axial direction, the annular wedge 6' and the impeller boss part 2' b
A wedge action is generated on the sliding surface S between the two parts 6' and 2' b
Although the connection is strong, no tightening force is generated in the centripetal direction, so there is no function of fixing the sliding surface between the shaft hole 3' and the impeller shaft l'a in the circumferential direction, and the impeller The anti-rotation effect cannot be expected. In order to prevent the impeller from rotating in this device, it is necessary to fit the inner peripheral surfaces of the shaft hole 3' and the annular wedge 6' into the outer peripheral surface of the impeller shaft 1'a in a static fit. This requires high-precision grinding, which increases production costs. Also, the impeller shaft 1'
Since the structure is such that the impeller is fixedly attached to the impeller, it is extremely difficult to remove the impeller once it has been fitted, and there is an inconvenience in that it is not possible to immediately replace the impeller.

Pumps used underwater are subject to significant wear on their impellers due to the suction of dirt and debris, and if they become worn out, they must be replaced with new impellers to prevent deterioration in pump performance. Therefore, it is important that the impeller fixing device in a submersible pump has a structure that is easy to remove.

[Object of the invention] The object of the invention is to effectively prevent rotation of the impeller,
Moreover, it has excellent processability and can be produced at low cost,
An object of the present invention is to provide an impeller fixing device that can be easily attached to and removed from an impeller shaft.

[Structure of the Invention] The impeller fixing device according to the present invention has a shaft hole in the boss portion of the impeller that is loosely engaged with the impeller shaft, and a pressurizing slope of the annular wedge described later and a sliding surface in front of the shaft hole. A slanted pressure receiving surface in contact with the shaft hole is provided eccentrically, and the pressurizing slope of the annular wedge is inserted from the tip of the impeller shaft along the slanted pressure receiving surface, and is screwed onto the tip of the impeller shaft. By tightening the tightening nut in the axial direction, the inclined pressure receiving surface is pressed against the pressurizing slope, and one side of the inner peripheral surface of the shaft hole is eccentrically moved toward one side of the outer peripheral surface of the impeller shaft. It is configured to be pressed into contact.

[Example] Embodiments will be described below with reference to the drawings.

1 is a motor shaft, 1a is an impeller shaft derived from the motor shaft 1, 1b is a step formed at the neck of the impeller shaft 1a,
IC is a male screw carved into the tip of the impeller shaft 1a.

2 is an impeller, 2b is a boss portion of the impeller 2, and 3 is a shaft hole drilled in the boss portion 2b so as to play with the impeller shaft 1a, and is eccentric to the inclined pressure receiving surface 5 described later. The diameter of the hole is slightly larger than that of the impeller shaft 1a. In FIGS. 3 and 8, Pl is the hole center of the shaft hole 3, and P is the center of an arc forming the circumferential surface of the annular groove 4, which will be described later.

Reference numeral 4 denotes an annular groove recessed in front of the shaft hole 3 with slight eccentricity, and in the embodiments shown in FIGS. 1 and 2, the circumferential surface of the annular groove 4 is formed into an inclined pressure receiving surface 5. In the embodiments shown in FIGS. 6 and 7, the outer peripheral surface of the front half of the impeller shaft 1a is formed into an inclined pressure receiving surface 5. The angle of inclination of these inclined pressure receiving surfaces 5 is made to match the angle of inclination of the annular wedge 6.

The annular wedge 6 has either one or both of its inner circumferential surface or outer circumferential surface formed into a pressurizing slope 7, and its inclination angle is made to match the inclination angle of the inclined pressure receiving surface 5.

FIG. 11 [A] is an example in which only the outer circumferential surface of the annular wedge 6 is formed as a pressure slope 7, and this annular wedge 6 is used when an inclined pressure receiving surface 5 is formed on the circumferential surface of the annular groove 4. be done. Note that the inner diameter of this annular wedge 6 is formed to be slightly smaller than the outer diameter of the impeller shaft 1a.

FIG. 11 [B] shows an example in which only the inner circumferential surface of the annular wedge 6 is formed as a pressurizing slope 7, and when the inclined pressure receiving surface 5 is formed on the outer circumferential surface of the front half of the impeller shaft 1a, this annular wedge 6 is used. Note that the outer diameter of this annular wedge 6 is formed to be slightly smaller than the groove diameter of the annular groove 4.

FIG. 11 [C1 is an example in which pressure slopes 7 are formed on both the inner and outer circumferential surfaces of the annular wedge 6, and the impeller shaft 1a
The annular wedge 6 is used when an inclined pressure receiving surface 5 is formed on the outer circumferential surface of the front half and on the curved surface of the annular groove 4, respectively.

Reference numeral 8 denotes a tightening nut, which is screwed into a male screw IC carved in the tip of the impeller shaft 1a, and by tightening this in the axial direction, the impeller 2 is attached to the impeller shaft 1a via the annular wedge 6. By fixing and releasing the tightening, the annular wedge 6 and the impeller 2 can be extracted from the impeller shaft 1a.

[Function] As shown in Fig. 2 and Fig. 7, the shaft hole 3 is connected to the impeller shaft 1.
a, so that the back surface of the boss portion 2b comes into contact with the stepped portion 1b, and the annular wedge 6 is inserted into the annular groove 4 from the tip of the impeller shaft 1a, as shown in FIGS. 1 and 6. Impeller axle 1a
When the tightening nut 8 is screwed onto the male screw 1c from the tip end and tightened in the axial direction, the annular wedge 6 is pushed in by the thrust, and the pressure inclined surface 7 comes into pressure contact with the inclined pressure receiving surface 5, and the impeller shaft A pressing force F is generated in the centripetal direction with respect to 1a, and one side of the inner circumferential surface of the shaft hole 3 is also eccentrically pressed against the impeller shaft 1a, generating a pressing force F in the centripetal direction. A contact surface g is formed. Furthermore, in the embodiment shown in FIG. 1, a non-contact surface g is also formed between the inner circumferential surface of the annular wedge 6 and the impeller axle 1a,
In the embodiment shown in FIG. 6, a non-contact surface g is also formed between the outer peripheral surface of the annular wedge 6 and the peripheral surface of the annular groove 4. In this way, the impeller 2 is firmly fixed to the impeller shaft 1a due to the partial press-fitting state.

Then, by removing the tightening nut 8 and the eccentric ring groove wedge 6,
The centripetal pressing force F exerted on the impeller shaft la by the inner peripheral surface of the shaft hole 3 disappears, and the impeller 2 can be easily extracted from the impeller shaft la.

[Effects of the Invention] According to the fixing device of the present invention, a pressing force is applied in the centripetal direction, and the impeller is prevented from rotating due to the partial press-fitting state having a non-contact surface. It is extremely easy to attach to and remove from the axle, and the fitting structure is flexible, so there is no need for high-precision grinding of the fitting surface as in conventional fixing devices. It has the advantage of being possible.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional side view of the main part of an embodiment of the device of the present invention, Fig. 2 is a longitudinal sectional side view of the main part of the embodiment shown in Fig. 1 with the tightening nut removed, and Fig. 4 is a sectional view taken along line AA in FIG. 1, FIG. 5 is a sectional view taken along line BB in FIG. 1, and FIG. 6 is a sectional view taken along line BB in FIG. FIG. 7 is a longitudinal sectional side view of the main part of another embodiment of the device of the present invention, and FIG. 7 is a longitudinal sectional side view of the main part showing the embodiment of FIG.
The figure is a vertical sectional side view of the main part of the impeller in the embodiment shown in FIG.
9 is a sectional view taken along the line CC in FIG. 6, FIG. 10 is a sectional view taken along the line DD in FIG. 6, and FIG. 11 is a longitudinal sectional side view of the annular wedge in the device of the present invention, [A] is a case in which only the outer peripheral surface is formed as a pressure slope, [B] is a case in which only the inner peripheral surface is formed as a pressure slope, and [C] is a case in which pressure slopes are formed on both the inner and outer peripheral surfaces. An example of this is shown below. 12th
13 is a longitudinal sectional side view of the essential parts of a known impeller fixing device, FIG. 13 is a longitudinal sectional side view of the essential parts of the impeller in the device shown in FIG. 12, and FIG. 14 is a longitudinal sectional side view of the annular wedge in the device shown in FIG. 12. , FIG. 15 is a cross-sectional view taken along line E-E in FIG. 12,
FIG. 16 is a sectional view taken along line FF in FIG. 12. 1a... impeller shaft, 2... impeller, 3... shaft hole, 5... inclined pressure receiving surface, 6... annular wedge, 7...
...Pressure slope, metered tightening nut.

Claims (1)

[Claims] The shaft hole (3) that fits with the impeller shaft (1a) is inserted into the impeller (2).
The boss portion (2b) of the shaft hole (3) is provided with an inclined pressure-receiving surface (5) in sliding contact with the pressure slope (7) of the annular wedge (6) described later in front of the shaft hole (3). and an annular wedge (6
) from the tip of the impeller shaft (1a) along the inclined pressure receiving surface (5).
) by tightening the tightening nut (8) threaded on the tip of the shaft in the axial direction, the inclined pressure receiving surface (5) is pressed against the pressure slope (7), and the inner circumference of the shaft hole (3) is pressed. An impeller fixing device characterized in that one side of the surface is eccentrically pressed against one side of the outer peripheral surface of an impeller shaft (1a).